From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <ast@kernel.org>, <daniel@iogearbox.net>
Cc: <andrii@kernel.org>, <kernel-team@fb.com>
Subject: [PATCH bpf-next 04/13] libbpf: don't call libc APIs with NULL pointers
Date: Tue, 23 Nov 2021 16:23:16 -0800 [thread overview]
Message-ID: <20211124002325.1737739-5-andrii@kernel.org> (raw)
In-Reply-To: <20211124002325.1737739-1-andrii@kernel.org>
Sanitizer complains about qsort(), bsearch(), and memcpy() being called
with NULL pointer. This can only happen when the associated number of
elements is zero, so no harm should be done. But still prevent this from
happening to keep sanitizer runs clean from extra noise.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
tools/lib/bpf/libbpf.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index af405c38aadc..23f84757c806 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -3369,7 +3369,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
/* sort BPF programs by section name and in-section instruction offset
* for faster search */
- qsort(obj->programs, obj->nr_programs, sizeof(*obj->programs), cmp_progs);
+ if (obj->nr_programs)
+ qsort(obj->programs, obj->nr_programs, sizeof(*obj->programs), cmp_progs);
return bpf_object__init_btf(obj, btf_data, btf_ext_data);
}
@@ -5816,6 +5817,8 @@ static int cmp_relo_by_insn_idx(const void *key, const void *elem)
static struct reloc_desc *find_prog_insn_relo(const struct bpf_program *prog, size_t insn_idx)
{
+ if (!prog->nr_reloc)
+ return NULL;
return bsearch(&insn_idx, prog->reloc_desc, prog->nr_reloc,
sizeof(*prog->reloc_desc), cmp_relo_by_insn_idx);
}
@@ -5831,8 +5834,9 @@ static int append_subprog_relos(struct bpf_program *main_prog, struct bpf_progra
relos = libbpf_reallocarray(main_prog->reloc_desc, new_cnt, sizeof(*relos));
if (!relos)
return -ENOMEM;
- memcpy(relos + main_prog->nr_reloc, subprog->reloc_desc,
- sizeof(*relos) * subprog->nr_reloc);
+ if (subprog->nr_reloc)
+ memcpy(relos + main_prog->nr_reloc, subprog->reloc_desc,
+ sizeof(*relos) * subprog->nr_reloc);
for (i = main_prog->nr_reloc; i < new_cnt; i++)
relos[i].insn_idx += subprog->sub_insn_off;
--
2.30.2
next prev parent reply other threads:[~2021-11-24 0:23 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-24 0:23 [PATCH bpf-next 00/13] Fix sanitizer-reported libbpf and selftest issues Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 01/13] tools/resolve_btf_ids: close ELF file on error Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 02/13] libbpf: fix potential misaligned memory access in btf_ext__new() Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 03/13] libbpf: prevent UBSan from complaining about integer overflow Andrii Nakryiko
2021-11-25 22:21 ` Daniel Borkmann
2021-11-25 23:19 ` Daniel Borkmann
2021-11-26 1:23 ` Andrii Nakryiko
2021-11-24 0:23 ` Andrii Nakryiko [this message]
2021-11-24 0:23 ` [PATCH bpf-next 05/13] libbpf: fix glob_syms memory leak in bpf_linker Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 06/13] libbpf: fix using invalidated memory " Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 07/13] selftests/bpf: fix UBSan complaint about signed __int128 overflow Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 08/13] selftests/bpf: fix possible NULL passed to memcpy() with zero size Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 09/13] selftests/bpf: prevent misaligned memory access in get_stack_raw_tp test Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 10/13] selftests/bpf: fix misaligned memory access in queue_stack_map test Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 11/13] selftests/bpf: prevent out-of-bounds stack access in test_bpffs Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 12/13] selftests/bpf: fix misaligned memory accesses in xdp_bonding test Andrii Nakryiko
2021-11-24 0:23 ` [PATCH bpf-next 13/13] selftests/bpf: fix misaligned accesses in xdp and xdp_bpf2bpf tests Andrii Nakryiko
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